Conventional automotive latch assemblies often employ a mixture of flexible cables for actuating the latch, combined with rigid rod linkages for driving the lock/unlock function of the latch. A problem with rod linkages arises from the fact that such linkages are susceptible to tampering by thieves, who are sometimes able to open the door of a vehicle by applying a tool to a rigid linkage so as to move the door latch to its unlocked position. A system according to the present invention obviates this problem because the push-pull cable used to move the latch assembly into and out of the locked position is resistant to manipulation by means of a jimmying tool. Moreover, with the present inventive lock system, when the latch has been moved into the locked position, a blocker pin prevents the lock from being jimmied into the unlocked state. This results in part because attempts to jimmy the latch will cause the key cylinder to separate from an enclosed component containing the locking/unlock mechanism, thereby preventing unauthorized actuation of the lock assembly.